1. Field of the Invention
The present invention relates to compositions which comprise, in a physiologically acceptable medium, at least one sapogenin chosen from diosgenin and hecogenin, or a derivative or a natural extract containing the same, and at least one xanthine base. The present invention also relates to the use of such compositions.
2. Discussion of the Background
Sapogenins are compounds resulting from the acidic hydrolysis of saponosides, which are themselves heterosides of very high molecular weight present in the plant kingdom. Among the sapogenins which may be mentioned in particular are: diosgenin, hecogenin, smilagenin, sarsapogenin, tigogenin, yamogenin, and yuccagenin.
These compounds have in common a steroidal structure comprising a variable number of hydroxyl and/or oxo substituents and/or a variable number of double bonds. They are known as natural chemical precursors of steroidal hormones and are described, in this respect, as constituents of choice for various cosmetic or pharmaceutical preparations.
Diosgenin, or spirost-5-en-3-beta-ol, can be extracted from fenugreek or from various Dioscorea plants, for example from the root of wild yam. Diosgenin has been described in particular as being usable in slimming compositions, on account of its ability to inhibit the storage of biochemical lipid material in adipose tissue (see, FR-2 786 097).
Cosmetic compositions for promoting epidermal renewal, which combine alfalfa sapogenins with various active agents including xanthine bases, are known from U.S. Pat. No. 5,770,223. These compositions are intended to combat the effects of ageing of the skin and to stimulate restoration of the hair or to prevent hair loss. These sapogenins differ chemically from those present, in particular, in wild yam and agave. Moreover, the compositions obtained in U.S. Pat. No. 5,770,223 are not described as being capable of having a slimming effect.
Thus, there remains a need for compositions which have a slimming effect even when applied topically. There also remains a need for compositions and methods which are effective for preventing and/or combating cellulite and for refining the figure or the contours of the face.